Signaling pathways involved in LPS induced TNFalpha production in human adipocytes

<p>Abstract</p> <p>Background</p> <p>The development of obesity has been linked to an inflammatory process, and the role of adipose tissue in the secretion of pro-inflammatory molecules such as IL-6 or TNFalpha has now been largely confirmed. Although TNFalpha secretion by adipose cells is probably induced, most notably by TLR ligands, the activation and secretion pathways of this cytokine are not yet entirely understood. Moreover, given that macrophagic infiltration is a characteristic of obesity, it is difficult to clearly establish the level of involvement of the different cellular types present within the adipose tissue during inflammation.</p> <p>Methods</p> <p>Primary cultures of human adipocytes and human peripheral blood mononuclear cells were used. Cells were treated with a pathogen-associated molecular pattern: LPS, with and without several kinase inhibitors. Western blot for p38 MAP Kinase was performed on cell lysates. TNFalpha mRNA was detected in cells by RT-PCR and TNFalpha protein was detected in supernatants by ELISA assays.</p> <p>Results</p> <p>We show for the first time that the production of TNFalpha in mature human adipocytes is mainly dependent upon two pathways: NFkappaB and p38 MAP Kinase. Moreover, we demonstrate that the PI3Kinase pathway is clearly involved in the first step of the LPS-pathway. Lastly, we show that adipocytes are able to secrete a large amount of TNFalpha compared to macrophages.</p> <p>Conclusion</p> <p>This study clearly demonstrates that the LPS induced activation pathway is an integral part of the inflammatory process linked to obesity, and that adipocytes are responsible for most of the secreted TNFalpha in inflamed adipose tissue, through TLR4 activation.</p

The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis

Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools. Methods: In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST. Results and Conclusion: The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events

Modulation of inflammation in fat tissue (potential involvement in chemically induced neurodegeneration)

L'obésité est un facteur important de risque pour de nombreuses pathologies dont le syndrome de résistance à l'insuline. Le tissu adipeux blanc (TAB) est considéré comme un organe endocrine produisant des adipokines. Le but de ce travail a été d'étudier l'effet d'un neurotoxique, le triméthylétain (TMT), et d'une molécule anti-inflammatoire, le Palmitoylethanolamide (PEA), sur l'inflammation produite par le TAB. Le TMT induit une production de cytokines pro-inflammatoires dans le TAB in vitro et in vivo, démontrant que des types cellulaires du TAB sont capables de répondre à ce composé. De plus, en association avec une concentration sérique élevée de TNFa, la lésion hippocampale ainsi que l'activation des astrocytes et des microglies ont été plus importantes chez des souris agouti que chez les souris contrôles, après traitement au TMT. L'effet du PEA a également été étudié et cette molécule inhibe la sécrétion de TNFa après induction par du lipopolysacharide in vitro et in vivo, suggérant que le PEA pourrait être étudié pour des applications thérapeutiques anti inflammatoire dans les pathologies associées à l'obésité.Obesity is a significant risk factor for several diseases including the insulin resistance syndrome. White fat tissue (WAT) is considered as an endocrine organ with the capacity to produce adipokines. The aim of this work was to study the effects of a neurotoxic agent on WAT s inflammation and to investigate the effect of an anti-inflammatory drug on WAT. We used, Trimethyltin (TMT), a neurotoxin known to induce an inflammatory response in the CNS and Palmitoylethanolamide (PEA), an anti-inflammatory drug. TMT induced the production of pro-inflammatory cytokines in WAT both in vitro and in vivo, demonstrating that cell types from the WAT are capable of responding to a neurotoxin. In addition, associated with TNF- level increase in the serum, the severity of hippocampal damage and activation of glial cells were more pronounced in agouti than in control mice. We also tested the effect of PEA on adipocytes and the results showed that this molecule inhibits TNF- secretion induced by Lipopolysaccharide both in vitro and in vivo, suggesting that PEA could be explored for therapeutic purposes as an anti-inflammatory drug for obesity associated diseases.SAINT DENIS/REUNION-Droit Lettre (974112101) / SudocSudocFranceReunionFRR

Method Development: A non-stereotactic device based method for CSF extraction from cisterna magna in rats.

Biomarker discovery has traditionally been done from serum. However, the problem with serum is that we get high abundance proteins like albumin in large quantities. These high abundance biomarkers mask the presence of biomarkers which are present in minute quantity. The aim of biomarker discovery from CSF is that it would give us rather clear repertoire of biomarkers which are of neurological importance and specific to the CNS. In this work, we propose to standardize a lab protocol for extraction of CSF from Rat brain (cisterna magna). There are two different procedures for extraction of CSF. One by lumber puncture method without sacrificing the rat and the other method is serial extraction from the cisterna magna region. The cisterna magna is located in the lowermost portion of brain from where the spinal cord starts. Our aim was to adapt the second protocol to extract the CSF from in house Rat repository. In the first step we had tried our method on dead experimented albino Wistar rats. In the next step we tested it on 12 live albino Wistar rats

Growth inhibitory, apoptotic and anti-inflammatory activities displayed by a novel modified triterpenoid, cyano enone of methyl boswellates

Triterpenoids are pentacyclic secondary metabolites present in many terrestrial plants. Natural triterpenoids have been reported to exhibit anti-inflammatory and anti-carcinogenic activities. Here, we show that modifications of ring A of boswellic acid (2 cyano, 3 enone) resulted in a highly active growth inhibitory, anti-inflammatory, pro-differentiative and anti-tumour triterpenoid compound called cyano enone of methyl boswellates (CEMB). This compound showed cytotoxic activity on a number of cancer cell lines with IC50 ranging from 0.2 to 0.6 mu M. CEMB inhibits DNA synthesis and induces apoptosis in A549 cell line at 0.25 mu M and 1 mu M concentrations, respectively. CEMB induces adipogenic differentiation in 3T3-L1 cells at a concentration of 0.1 mu M. Finally, administration of CEMB intra-tumourally significantly inhibited the growth of C6 glioma tumour xenograft in immuno-compromised mice. Collectively, these results suggest that CEMB is a very potent anti-tumour compound

A Molecular Web: Endoplasmic Reticulum Stress, Inflammation, and Oxidative Stress

International audienceExecution of fundamental cellular functions demands regulated protein folding homeostasis. Endoplasmic reticulum (ER) is an active organelle existing to implement this function by folding and modifying secretory and membrane proteins. Loss of protein folding homeostasis is central to various diseases and budding evidences suggest ER stress as being a major contributor in the development or pathology of a diseased state besides other cellular stresses. The trigger for diseases may be diverse but, inflammation and/or ER stress may be basic mechanisms increasing the severity or complicating the condition of the disease. Chronic ER stress and activation of the unfolded-protein response (UPR) throughendogenousorexogenousinsultsmayresultinimpairedcalciumandredoxhomeostasis, oxidative stress via protein overload thereby also influencing vital mitochondrial functions. Calcium released from the ER augments the production of mitochondrial ReactiveOxygenSpecies(ROS).ToxicaccumulationofROSwithinERandmitochondriadisturbs fundamental organelle functions. Sustained ER stress is known to potentially elicit inflammatoryresponsesviaUPRpathways.Additionally,ROSgeneratedthroughinflammationor mitochondrial dysfunction could accelerate ER malfunction. Dysfunctional UPR pathways have been associated with a wide range of diseases including several neurodegenerative diseases, stroke, metabolic disorders, cancer, inflammatory disease, diabetes mellitus, cardiovascular disease, and others. In this review, we have discussed the UPR signaling pathways, and networking between ER stress-induced inflammatory pathways, oxidative stress, and mitochondrial signaling events, which further induce or exacerbate ER stress

White Fat Tissue, Obesity, and Possible Role in Neurodegeneration

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CDDO and ATRA Instigate Differentiation of IMR32 Human Neuroblastoma Cells

International audienceNeuroblastoma is the most common solid extra cranial tumor in infants. Improving the clinical outcome of children with aggressive tumors undergoing one of the multiple treatment options has been a major concern. Differentiating neuroblastoma cells holds promise in inducing tumor growth arrest and treating minimal residual disease. In this study, we investigated the effect of partial PPARγ agonist 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO) on human neuroblastoma IMR32 cells. Our results demonstrate that treatment with low concentration of CDDO and particularly in combination with all trans retinoic acid (ATRA) induced neurite outgrowth, increased the percentage of more than two neurites bearing cells, and decreased viability in IMR32 cells. These morphological changes were associated with an increase in expression of bonafide differentiation markers like β3-tubulin and Neuron Specific Enolase (NSE). The differentiation was accompanied by a decrease in the expression of MYCN whose amplification is known to contribute to the pathogenesis of neuroblastoma. MYCN is known to negatively regulate NMYC downstream-regulated gene 1 (NDRG1) in neuroblastomas. MYCN down-regulation induced by CDDO correlated with increased expression of NDRG1. CDDO decreased Anaplastic Lymphoma Kinase (ALK) mRNA expression without affecting its protein level, while ATRA significantly down-regulated ALK. Antagonism of PPARγ receptor by T0070907 meddled with differentiation inducing effects of CDDO as observed by stunted neurite growth, increased viability and decreased expression of differentiation markers. Our findings indicate that IMR32 differentiation induced by CDDO in combination with ATRA enhances, differentiation followed by cell death via cAMP-response-element binding protein (CREB) independent and PPARγ dependent signaling mechanisms